Jansson



J. JANSSON June 28, 1960 AUTOMATIC CONTROLLER FOR FACTORS OF COMBUSTION Filed DBC. 18, 1958 5 Sheets-Sheet l J. JANSSON `lune 28, 1960 AUTOMATIC CONTROLLER FOR FACTORS OF COMBUSTION 5 Sheets-Sheet 2 Filed Dec.

J. JANSSON `lune 28, 1960 AUTO 5 Sheets-Sheet 5 Filed Dec.

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5 Sheets-Sheet 4 Zin/U elbl QI Jl/QSQS 017/ June 28, 1960 J. JANSSON 2,942,784

AUTOMATIC CONTROLLER FOR FACTORS OF' COMBUSTION Filed Dec. 18. 1958 5 Sheets-Sheet 5 United States Patent O AUTOMATIC CONTROLLER FOR FACTORS OF COMBUSTION John Janssen, Stockholm, Sweden, assignor to AB. A Ekstroms Maskinalfar, Stockholm, Sweden' Filed Dec. 18, 1958, Ser. No. 781,243

Claims priority, application Sweden Apr. 26, 1957 Claims. (Cl. 236-26) This invention relates to controls means and especially to automatic control for the several factors of combustion for devices such as boilers or the like, and is a continuation-in-part of application Serial No. 654,192, tiled April 22, 1957, now* abandoned.

From experience it is known that the amount of air required for complete combustion of fuel is in excess of the theoretical amount of air and that, at high com-V bustion rates, the excess of air required over the theoretical amount is less than it is at low combustion rates. Also the excess required will be different for diierent fuels.

It has further become the practice to use two different fuels in the boiler, in which case it may be desirable to use a preponderance of one fuel at standby or light loads, and as the load builds up to vary the proportion between the fuels and to use a preponderance of the other fuel at heavy loads.

It will be understood then that there may be several factors contributing to the combustion in a device suchv as a boiler that, as the load on the boiler varies, must each be also varied, one at a different rate than another.

It is desirable also that the engineer operating the boiler may know at any time thek operating conditions of the boiler and to be able to control not only the conditions of supply of the several requirements for combustion at the particular conditions of steaming, but also to be able to set the device so that, as conditions of steaming change, the controls for each of the factors of combustion will be adjusted to satisfy the new conditions according to the desires of the engineer.

It is a primary object of the present invention to providecontrol means from which each factor .of combustion, for instance of a iboiler, may be controlled for any steaming condition so that, as the load varies, each factor will be rautomatically controlled to vary in. the correct proportion with4 respect to the other factors so 'that the boiler will be operated acording'to the engineers ,d e-V sires under allloads.

It is a further object of the invention to 4Vprovide an automatic fcontr'ol in'which the control of ,each factorfor each load condition from standby to full load may b e Pre-.Sat t0 vary as required under the Changing Conditionslt is a' further object of the invention to provide automticomrol means having .a graphical representation Sarrieri that infermi ,the Op'erater of the .Setting of the.

CQefrOlS wider the existing load and also informs the operator what the rs ettingfof Changed laad wndtisnsa l Othsrvand furtherbiccts andv advantages ,Willl appear fronr therfollowing specificationV taken with vthe accompanying drawings, in which like characters of reference referto similar parts in the several views, and in which: Fig. 1 ,is a fragmentary .perspective view Villustrating the invention, Y `l-`.ig, 2 is a .diagrammatic representation of the inven- 'fiQn using a Huid Operating medium, and

Figs."3, 4 and 5 vare 'diagrammatic representations il# the controls willbeunder any lustrating the invention using electricity as the operating medium.

In Fig. 1 the device comprises a carriage 101 that is mounted to move easily along a guide bar 102, a servomotor means 103, shown here as a movable piston in a stationary cylinder, connected to carriage 101 by means of'piston rod 136.

In vlfront of the carriage 101 and supported by the stationary structure of which guide bar 102 is a part are two vertical supports 146 and 147.

Mounted in supports 146 and 147 opposite carriageV 101 are pairs of adjusting screws 113-114, 1154-116, and 117-1-18 that, upon rotation, may be advanced toward or retracted from the carriage 101. Each pair of` adjusting screws is arranged to support one end of a straight edge 110, 111 and 112, respectively, that Vextends in parallel planes normal to the plane of carriage 101.` These straight edges act as cam means to operate control elernents 104, 105, and 106, as will appear below.

On carriage 101 are three control elements 104, A105V and 106, each mounted with its axis in the plane of one of the straight edgesor cam bars 110, 11'1 and 112,.- Each control element is provided with a feeler elementV shown asarod 107, 108 and 109, respectively, that may. be spring pressed outwardly toward the straight edges and that bear .respectively on cam means 110, 111 and I112. It will be understood, therefore, that as the carriage 101 moves along guide bar 102 the plunger rod 109, for instance, will slide along its straight edge or cam 112 and'if the end -of straight edge 112 adjusted `by adjusting screw 117 is farther from carriage 101 as it moves along guide bar 102 than is the end supported by adjusting screw 118, then, as Athe carriage 101 moves from left to light the plunger 109 will Ibe progressively pushedl into its control means 106 and, as carriage 101 moves from right to left, the plunger ,-109 will progressively emerge from its control means 106 under the influence of the spring. 'Ihe straight edge 112 could be adjusted so that the end adjusted by screw 117 is closer to carriage 101 and the end adjusted by screw 118 is Vfarther from carriagej101 according to the results desired.

Straight edges y and 1,11 are similarly adjustable and each inuences its appropriate plunger 108 or 107, according to the angle of the straight edge with respect to the plane of travel of carriage 101 and, of courseby its proximity as a whole to the plane of travel of carriage 101.

In order to have available a graphical, representation of the position of the straight edges with respect to the plane of carriage 1011, each adjusting screw 11,3, 114; 115, 116; 117 and :113 is provided with a small pinion 1 19, y120; 121, I122; 123 Vand 124. Each pinion associated with lanadjusting screw meshes with a rack 126; 127, 128; and 129, 130, so it will be seen'that 'as one engl of any straight edge is moved toward the plane of carriage 10,1` by rotation of its adjusting screw theVVV rack associated'with, V,that adjusting screw is moved upwardlyY or downwardly proportionately by rotation of the y its associated. racks, or may be non-elastic and vsecured to one end and the vother end-extending over ,a pulley and .counterweighted These lelements may also beof stiff` wire in whichrcase they are pivoted at one end to one "of the racks and .the other end `extends slidably througl'rl a loop on the associated rack as seen in Figs. 2 and 5.

The `threads .or Ywires 13 1, 132 and-133 appear at@ l screen which, of course, may be marked Iwith suitable indiciato give specific ,significance lto theloeation of the threads rwth@V ser-sen,4 Thetrascf thethreeds i131, :.la

and'133 on the window 135 igraphically describe 'thea posifieri ad Slope fine saaigm edges 110,-111 and 112,

respectively. In order to have a graphical representation of the instantaneous setting of each of the control elements 104, 105 and 10611nderthe -iniluence .ofstraigltt` edges 110, 111 and 112 respectively, a wire Y134 is mounted to move with the control elements yas they are Y,moved along guiderbar 1,02V and to provide a visible line or Aindicia at VVscreen Y135 which, as is clear in Fig.Y 1,*-intersecgts` the tracespof threads 131, 132 and 133. `These intersec-Y tions graphically illustrate the degree to which the plungerV rods 107, 108 and 109 have each beenpushed linto its control means V104, 105 or 1 06 by its movement along its corresponding'straight edge. Cylinder 103 is a mear'is,l which, .through piston rod 136, moves carriage 101 back and forth along guide bar i102. v

Y If control element 106, for instance, controls fuel Yto aj burner, 'it is Y`at once apparent that as the carriage v101 moves along guide bar 102 the plunger rod 1094bea1ing,V

against straight edge 112 is inserted further and further into control element 106 asV the carriage moves toward theV right and will emerge more and more as the carriage.

trace of wire 13,4 as it crosses the trace of thread 1733, the operator will be advised as to the instantaneous flow of fuel to the burner and will be advised as to the variations of such flow as they occur. The operator will, because` there is a graphical representation of the condition or position of each of the control elements '104, 105 and 1706,. be able to visualize-the conditions as they exist momen-A tarily, yand how theyY will each be changed with relation to each other as boiler conditions vary.

r[he position of the carriage 101 on the guide bar. 102 may depend on the boiler pressure, as will be seen below.

'Ihe graduations on the glass plate 135 parallel with the.

racks mark the'boiler 'load or pressure that is indicated by the wire 134 carried by carriage 101, while the graduation of the glass plate `at right angles to theracks marks the feeding of the various sources such as lair, fuel, etc. indicated by the threads r131,132 and 133.

When the adjustment screws 113, 114, 115, 116, 117 and 118 are screwed out as much as possible, the straight edges 110, 111 and 112 will be parallel in relation to the guide bar 102, and the tensionV in the springs of the control elements will correspond to the lowest outgoing control pressure, whereby the threads 131, 132 ,and =133 uniting the three pairs of racks will be located opposite each other and also opposite the graduation line lowest on the glass plate 135 and at right angles to the racks. When, on the other hand, the adjustment screwsl are entirely screwed in, the straight edges 110, 111 and 112 will still be located parallel in relation to the guide bar 102, but the threads 131, 132 Aand 133 will be located opcontrol elements will depend` upon the position of straight edges 110, 111 and 112 and the momentary control pressures `are indicated at that point where the wire 134 ntersects the respective threads 131, 132, 133, since the posi- Ytion of the wire 134 is dependent on the adjustment of the servo-motor 103. Instead of reading as control pressures the graduations on window 135 are calibrated to read in appropriate units as, pounds per hour, for fuel, or c.f.,m. for `air, etc. t

The specific control means 104, 105 and 106 not of primary significance in the broad concept of the device.

a controlY system i using the invention, reference is made to Fig. 2 which shows a boiler 148, -a prsure converter 149 and 'a dia-' phragm actuated valve |.150. The pressure converter 149 is operated in this instance by means of pressure in lthe boiler. 5

The pressure converter 149 comprises a pressure sensitive diaphragm 151 which isV connected to the boiler 148 by means of a conduit or pipe 159, a diaphragm l152 'being acted upon by Ea control pressure medium from pipe r 155, -a rod153 connecting saidrdiaphragms Y (which are of diierent sizes so thel pressure from 15S may be low),

any outlet nozzle 154, a supply conduit or pipe 155 lfor t-hc pressure medium, saidV conduit or pipe being provided with a reduction valve 156 Yand a throttling nozzle 157.

The outgoing pressure from the pressure converter passes Y tothe burner, then, Iby watchingthermovement of theY through a tube 158 leading to the servo-motor v'103. l

When there is a decreasing pressure in the boiler, the

'nozzle 154.and apressure reduction .results-inthe conduit' 158 and in the` cylinder l103 which permits the spring 138 to press the piston 137, the rod 136, and the carriage 101 and control elements 104, 105 Aand 106 to the right to an extent corresponding to the pressure reduction. in .the cylinder 103. Since by adjustment of screwsw1f17vand 118 the straight edge 112 is caused to assume an oblique position, the pressure rod 109 is pressed into control element 106 and compresses the spring :140 as the carriage 101 is moved to theright.

The diaphragm operated valve 150 to control, for instance, fuel to the boiler, comprises a valve box 159, a

valve spindle 160, a diaphragm 161 and a spring 162.

The valve 150 andthe relay 106 of the device are connected to each other by means of a conduit 144.

A pressure medium is fed to the control element 106 through the reduction valve 143 via the exible conduit 142 and the throttle 145. Conduit 142' and pipe 155 may receive pressure medium from the same source. While no pressure is developed in the relay when the outlet nozzle 141 is not obstructed by the diaphragm 139, a pressure equalizing the pressure of spring is formed in the relay when, by means of plunger rod 109, theY 'spring 140 is pressed toward the Outlet nozzle 141.

Thereafter the pressure resulting from the throttling Vof 'nozzle 141 is transmitted through the liexible conduit 144 to the valve over diaphragm 161 which actuates the valve spindle to open the valve to the extent determined by the balance between the pressure on diaphragmv 161 and the strength of spring 162. Y

v It is seen, therefore, that as pressure in the boiler drops the' control element 106 is moved to the right soV the pressure in conduit 144 increases in the manner described above and actuates. the diaphragm motor valve 150 to increase the oil supply to the boiler in order to restore normal pressure conditions. In the case of increasing pressure in the boiler, the various moments of operation occur in a reverse manner. 'Iheeworking of the control devices with regard to the other variables controlled by control elements 104 and 105 follows the same principles. Y

By setting the several straight edges or cams 110, 111 and 112, therefore, the control of each of lthe-services to the boiler can be pre-set for every condition of opera.- tion. It will be noted, however, that in order to use the devieto ,automatically bring the boiler 4to a desired pressure andihold it there it isnecessal'y to adjust the balance between the spring 138 and the pressure in conduit 158. A simplevmeans to do bya meanssuch as threaded element 138, which may be provided with indicia so that its position will state the pressure. desired for boiler operation.

It isto be understood, however, that conditions other thanboiler pressure may be used as theY means to aetuate a servo-,motor 103. The differential pressure through a metering Qriiice couldbe used so that the control elements wouldbemovedinaccordance with the volume of steam used so that upon sudden use of more steam the boiler iire ,would be increased without waiting Yfor the boiler pressure Vto drop.Y Temperature also could be used, or several YfactQrscOuld beused to position the servo-motor 103.

Ihepresent application, however, is not concerned so much withthe -means to operate the servo-'motor as with the control means shown ,inV Fig. 1 that is operated by any appropriateservo-motor device.

-While thedevicedescribed above is operated by compressed Vairor pressurel oil it is, of course, also possible for the device to be operated by electrical impulses. Three Vembodiments for such operation are described below. y

Figure 3 shows yan embodiment in which instead of the control element 106 a' control element in the form of a solenoid 163 with a-movable iron core 164 is used, which iskept pressed against the straight edge or cam 112 by means of a spring 16,5,fthe solenoid being fed from an alternating current source 166. A valve 169, corresponding to valve 150 in- Fig. 2, is controlled by another solenoid 167 with an ironV core- 168 being kept in stretched position by means of a spring 170. Solenoid 167 is connectedin serieswith the solenoid 163. When the carriage 10,1 is moved to theright, the iron core 164 is pushed into the solenoid 163 which causes 4the current passing through said solenoid to decrease, saidY decrease being due to the fact that the same currentis also passing through the solenoid 167 and consequently the current also decreases in solenoid 167. The iron core 168 is therefore Vmovedgby means of the spring 5170 and the valve 169 opens. Ihe oblique position of the cam 112, which is determined by devices described above, can be read oiY as explained in connection with Fig. 1 with help ofthe traces of the adjustable threads on Vthe plate.

Figure 4 shows van embodiment in which the movement of avalve 180 is actuated by a servo-motor-178, the shunt winding of which is connected as a Wheatstone bridge with two adjustable resistors 17:1 and 175. I'he resistor 171 is controlled by means of sliding contact 172 electrically insulated and connected to a rod 173 which, by means of spring 174, is kept pressed against the straight edge 112. The resistor 175 is controlled by sliding contact 176 moved by a rack 177 which cooperates with a toothed wheel 181 fastened to the axle of servo-motor 178. The spindle of the valve 180 is rigidly connected to the rack 177. This device, as stated above, operates on the principle of a Wheatstone bridge, i.e., when the carriage is moved in one or the other direction, moving contact 172 along resistor 171, a certain unbalance in voltage occurs between the resistors 171 and 175. A current is therefore passed through the shunt winding 179| of the motor l178 in one or the other direction, and the motor operates to restore the balance. The sliding contact 176 is moved so that a balance in voltage is obtained and the 'shunt winding 179 becomes dead.

A further embodiment using electrical resistors is shown in Figure 5. As it appears from the iigures shown, the racks and indication plate are changed from the position in relation to the guide bar 102 that is shown in Fig. 1 and the aforementioned cams 110, 111 and 112, as well as all adjustable screws, are eliminated. The cam bars and plunger rods are replaced by contact rails 182, 183,

electrically insulated at 188 and 189 from the rods 190 and 191. The rods 190, l191 slide in the rails 192 and 193, -said'rails being fastened to the stationary guide bar 102. The adjustment of the valve 197, which may correspond to valve 15,0, is also here shown as a solenoid` valve.V 'Solenoid 194 `with movable core 195 is kept in a drawn-out or valve closed position by the spring 196 and connectedby arm 195 with the valve cone. During the Vmovement of the .carriage to the right the portion of the resistor 185.1b`eing connected becomes smaller and smaller, and asthe resistor is connected in series with the solenoid 194 the latter is activated by a current becoming stronger and-stronger, sothat the core 195 is drawn in deeper and deeper. During movement of the carriage to the left, the various operations'occur in a reverse manner.

The electrical embodiments described above of course require `electricalV equipment designed in such a Way that the position of the valve can be directly read off from the indicationY plate 135.

'Ihe control and indicating device described above showing three control elements can, of course, also be designed 'to include a greater number of control elements.

Too largev a number lof such control elements in one and the same device,however, will complicate the reading from the-indication vplateV owing to thelarge number of threads required. In `'such a case it is possible to make a relay Vin such a manner that `it gives an impulse to the servo-motor of a similar device or a similar device may operate'in parallel from the same impulse source.

Modifications lwithin thescope of the claims are possible. Thus, the glass'plate f135 may be replaced by a mirror, and the wire 134'may beY replaced by a sheet moved forwards by vthe carriage 101 so that a part of the illuminated window 135 is screened 0E.

While the device has been described in use as a control for afboilei', it will be apparent to those skilled in the control that the device of the present invention may be --used'in `many fields and that modifications can be made withoutdeparting from the scope of the invention as deed'in'the appended claims.

What is Aclaimed-is:`

1, -In a'devicel of the character described to control the supply of such factors as fuel and air necessary for combustion" i-n a boiler, a vservo-motor arranged to respond to the instantaneous operating conditions of a boiler, a movable element guided for straight line movement under the inuence of said servo-motor, the position of said movable element along said straight line being determined by said servo-motor in response to said operating conditions, an observation Window, iirst indicia means on said movable element forming a visible line on said window that moves parallel to itself as Said movable element moves, at least one relay element including a rod slidably mounted at right angles to the direction of movement of said movable element mounted on said movable element, said relay element being so constructed yand arranged as to control the supply of one of said factors necessary for combustion by axial movement of said rod, adjustable cam means extending inthe plane of movement of said rod generally in the direction of movement of said movable element, follower means operating between said rod and said cam means so that said rod follows said cam means as said rod is moved therealong, means to adjust the angularity of said cam means with respect to the direction of movement of said movable means whereby said relay element may be adjusted in accordance with the adjustment of said cam means when said movable element moves under the inuence of said servo-motor, and second indicia means operated'byA said means to adjust said cam means, said second indicia means forming a visible line on said window indicativeV of the adjusted position of saidA cam means whereby Vthe point of intersection of said lines formed by said rst and said second indicia means will indicate the instantaneous value of the controlled supply of .the factor necessary for combustion.

Y2. Means to simultaneously .and automatically adjusta plurality of control devices in conformity with a preselected program comprising a slide element, means tomove said slideelement, a plurality of control devices mounted on said slide element, each of said control devices includingan operating element movable in a direction normal to the direction of movement of said slide element to actuate said control devices, adjustable cam meansrfor each said operating element lying parallel to the line of movement of said operating elements, adjustable 4means for each said cam means to alter and preset the position and angle of said cam means with respect to the line of movement of each said operating element, a window, means mounted on saidslide element t-o form a iirst visible line on said window adapted to move parallel to itself as said slide element is-moved, and means associated with each said adjustable means to produce a further visible line onsaid windowrepresenting the position and angle of each said cam means with respect tothe line of motion of the associated control device whereby the intersection of said; rst visible line with said further visible line will indicate the instantaneous adjustment of each said control-.device and Y the several further visible lines willV give a graph of the adjustments of saidplurality ofr control devices as *saidV slide element is moved under the inlluence of said means to'move said slide element, said control-devices each being operatively connected to a device tobe controlled.

3. -A device of the character described comprising a carriage, a `guide bar, servo-motor means to move said carriage on said guide'bar, at least one relay' means rigidly mounted on said carriage, a pointer mounted on the carriage, a spring-actuated pressure rod extending from said relay so constructed and arrangedthat the position of said rod in the relay Ydetermines a signal coming from the relay, a straight edge, manually adjustable means comprising two adjustment screws extending towards and secured torsaid straight edge, follower means whereby said pressure rod slides'along said straight edge when said carriage moves alongsaid guide bar, a pair of lracks located at right anglesto and adjacent said adjustment screws, each said rack cooperating with the toothed wheel on one of said adjustment screws,

thread means connecting the .ends of said pair ofracks,

and a glass plate forming a diagram window applied in a plane adjacent the said pointer and the. said Ythread means, whereby by the position of the thread and of the pointer the adjustment of the relay can fbe read oi, thel said pointer being Yso positioned that it extends parallel with the racks.

"4'. A control device comprising a carriage mounted forllinear movement along a path, a plurality of control elements mounted on said carriage, each said control element comprising a -body housing adjustable controlv means, a feeler element mounted on Vsaidbody and connected to said adjustable control means in such a manner tha-t said control means is adjusted- `by the position of said feeler element with respect to said body, adjustable cam means for each said control elementslying generally parallel to the linear path of said carriage, each saidd cam means being associated with vandfin"camming-contact with the feeler element of'one of said control elements, whereby as said carriage is moved along said path each of said control elements are adjusted in accordance with the adjusted position of its associated cam means, a screen, a plurality of movable indicia mounted to be normally Vvisible on said screen, each said indicia beingassociated with one of said adjustable lcam means and having a profile similar to lche prole of the associated cam means, com-mon means to adjust the position of each said cam means and its associated indicia means, Whereby the position of said indicia means with respect to said screen is indicative of the position ofits associated *camv means with respect to its associated eeler'element.

5 rllhe device of claim 4, in which an indicia means is indicate the setting of the control means associated with' said one of said cam means.

References Cited in the tile of this patent UNITED STATES PATENTS l' 2,166,077 Y Spitzglass Y July 11, 1939 2,266,202 Heinkel D ec. 16, 1941 Y 2,375,831 Turchan et al May 15, 1945 Johnson f-- Apr. 14, 1953 v e ar 

